1. Field of the Invention
The present invention relates to photographic emulsions on substrates having a subbing or priming layer thereon.
2. Background of the Art
The construction of silver halide photographic elements has become an art that is an amalgum of many different sciences and technologies. Such varied disciplines as polymer chemistry, crystallography, physics, electrostatics, dye chemistry, coating technologies, and the like have to come into focus to produce what is to the consumer a simple snapshot.
Two complex problems that have traditionally been of concern to the photographic industry are adherence of the photographic emulsions to the substrates of choice (i.e., polymeric substrates such as polyester, polyolefin, or cellulosic ester bases and polymer coated paper bases such as white pigment filled polyolefin or polyvinylidene chloride coated paper). Another problem, particularly in high image content film which is processed mechanically is the development of static or triboelectric charges in the film which create spurious images.
Many different compositions, combinations of layers, and treatment of substrates have been proposed to effect better adhesion between emulsion layers and substrates as is evidenced by the number of patents in this technical area. A sampling of these patents include U.S. Pat. Nos. 3,271,345, 2,943,937, 4,424,273, 3,791,831 and the like. A great amount of work has also been directed in the photographic sciences to the elimination of electrostatic charges on photographic film. Examples of the diverse work done in this area includes U.S. Pat. Nos. 4,582,782, 3,884,699, 3,573,049 and the like.
Assorted handling problems (e.g., adhering of layers) are often addressed by the use of particulate matting agents in backside coatings or surface layers of photographic elements. Also sensitometric effects (e.g., lightscattering) are achieved by the use of particle-containing layers in photographic elements. These uses of particulate containing layers shown in U.S. Pat. Nos. 4,343,873, 4,144,064, 3,507,678, 4,022,622 and the like.
Typical photographic supports comprise a base material (e.g., polyester, cellulose triacetate, or paper) with a subbing layer on at least one surface to assist in the adherence of the gelatin layers, including the emulsion layers, to the base. Conventional subbing layers are described in U.S. Pat. Nos. 3,343,840, 3,495,984, 3,495,985 and 3,788,856.